Process for the treatment of vegetable fibers



' No Drawing.

' UNITED STATES PATENT OFFICE.

CHARLES SCHWARTZ, OF VILLEURBANNE, FRANCE, ASSIGNOR TO' SQCIETE GILLET &; FILS, OF LYON, RHGNE, FRANCE, A CORPORATION OF FRANCE.

PROCESS FOR THE TREATMENT OF VEGETABLE FIBERS.

dressing or glossing textile fabrics, which consists in impregnating them with a solution of cellulose in zinc chlorid and precipitating the cellulose upon the vegetable fiber by subsequent washing of the zinc chlorid (German Patent No. 84,513).

It has also been proposed to impart to cotton a luster similar to that of silk by treatment with alkaline solution of nitrocellulose (German Patent No. 98,602).

The present process for treating vegetable fibers is intended-to impart to them the character of wool, both physically as to the feel, appearance and caloric qualities and chemically as regards their aflinity and ab; sorbent capacity for dyestuffs.

This process is applicable to vegetable fibers of all kinds, in the raw state or bleached, and whether mercerized or not, at

any stage whatever in the operations to which they are subjected in the textile industry, either in the mass, or in the state of waste, lap, fleece, card-ends, yarns or fabrics.

This process consists in impregnating these vegetable fibers by means of a solution of cellulose, of any origin, in concentrated nitric-acid prefegbly of a concentration equal to or higher tharf 65 per cent, and in precipitating upon the fibers a slightly nitrated cellulose by washing these treated fibers by means of water. The product which is deposited upon the fiber contains I about 5 to 6 per cent.'of nitrogen.

It has been found that this precipitation of the nitrocellulose is more rapid and complete if, instead of treating the fibers soaked in the solution with water, they are treated withdilute solutions of acids or bases or with saline solutions. for example, or ammonia, sodium bisulfate, ammonium sulfate, sodium sulfate, or

sodium phosphate in 10 per cent. aqueous solutions, will give good results.

The .textile material impregnatedwith a solution of cellulose in nitric acid, 1s to be substance better.

The use of sulfuric acid,'

Specification of Letters Patent. Patented N 29, 1921,

Application fi1ed December 9, 1919. Serial No. 343,576.

treated with one of the baths indicated above, and then washed With water. The precipitation of nitrocellulose upon the vegetable fibers takes place instantaneously and, owing to this rapid action, the fibers absorb the Moreover the final washing is quicker and the recovery of the nitric acid is facilitated.

The temperature of the-cellulose solutions may be from 0 to approximately 25 centigrade, and the duration of contact ma vary within limits up to half an hour .witli corresponding concentrations of nitric acid, without any disadvantage as regards the result of the reaction.

The textile material remains sound and strong during the operation; this solution in excess may be expelled by pressure and the textile washed. I

After pressing "and washing the textile fiber, the nitrocellulose remains firmly, adherent to the steeped fiber and is definitlvely combined with the latter, forming a union which resists any mechanical or chemical operation which the treated fiber may have further to undergo.

1 The nitrocellulose absorbed by the fiber and precipitated upon and within the same, behaves thereafter quite differently from the case of a dressing or gloss upon the fiber.

The infiammability of the textile material when treated and dried is scarcely increased at all, so that there is no objection to its direct utilization. Denitration in accordance with-one of the known processes is not therefore necessary, but, if applied to certain kinds of fabrics treated by this process, it increases the wool-resembling character of the material.

The weight of deposit is greater or less according to the content of cellulose-matter in the solution. It is to be noted that'the use of celluloses, mercerized by alkalis or by acids or hydrolyzed, increases the solvent and absorbent power of the nitric acid.

The strength of resistance of the treated fiber is considerably increased by the process forming the subject of the invention. The

absorption of nitrocellulose produces moreover a large increase of weight and in fabrics a much denser gloss. The dye-absorbing power is much higher, even as regards basic colors, which dye the treated vegetable fiber easily and without the use of a mordant.

- more supple, becoming generally of the nature of wool.

This process of treatment is equally, advantageous for lap or fleece as for drawn stufi's and fabrics of all kinds, without distinction of quality, whetherplain, ornamented or worked.

Printeffects may also be obtained upon plain or drawn stuffs, either by direct impression, the fabric being impregnated with the cellulose solution at the desired parts and the nitrocellulose then precipitated at these parts by washing, or by the use of suitable resists or reserve pastes, such as kaolin, at the parts where the print-effectsare to be avoided, and by treatment with the cellulose solution and precipitation by washinvof the other parts.

he solution employed for the treatment of textile materials may for example be prepared in the following manner:

I. Introduce rapidly and with constant stirring, 30 grams of wood-pulp or cottonwaste, the whole being thoroughlydisintegrated and bleached, into 1000 grams of 81 per cent. nitric acid, at a temperature of 15 to 20 centigrade; after complete solution to a syrupy mass, add 112 grams of water.

II. Proceed as above, dissolving 50 grams of mercerized cellulose in 1000 grams of 83 per cent. nitric acid, and then add 250 grams of water. I

III. Prepare a solution as above, by dissolving 100 grams of hydrocellulose in 1000 grams of 81 per cent. nitric acid, and adding 112 grams of water. i

IV. Introduce 70 grams of mercerized cellulose into 750 grams of 75 per cent. nitric acid; leave for two hours and then remove about 460 grams of acid by decantation and pressure. Add the residue to 500 grams of 92 per cent. nitric acid,.or vice versa, solution being instantaneous, and then add 145 grams of water.

The viscous solutions prepared as above are allowed to cool to 15 to 20 centigrade, and are kept in a'cool place.

The treatment of the vegetable fibers is effected by introducing the textile material into the liquid of syrupy consistency, in which it is left fora certain time without tension; the liquid is then pressed or dried out and the material washed.

Solutions prepared in accordance with paragraphs I, III and IV are intended for fabrics of inferior quality (American cot ton); the solution prepared according to paragraph II is intended for use with fabricsof better quality, such as batiste (Egyptian cotton).

The time of impregnation of the textile material with the solution is in general 3 to 5 minutes, according to the nature and permeability of the material; it may be extended to half an hour without harm to the formed, I declare that what I claim, is

1. A process for the treatment of vegetable fibers with a view to impart to them the character of wool, both physically, as to the feel, appearance and caloric quality, and chemically, as regards their affinity and absorbent capacity for dyestuffs, said process consisting in impregnating the fiber with a solution of cellulose in concentrated nitric acid, and precipitating upon the fiber a slightly nitrated cellulose by washing with.

water.

2. A process for the treatment of vegetable fibers with a view to impart tothem the character ofwvool, both physically, as to the feel, appearance and caloric quality, and chemically, as regards their affinity and absorbent capacity for-dyestuffs, said process consisting in impregnating the fiber with a solution of cellulose in concentrated nitric acid, at a concentration of at least 65%, and

in precipitating upon the fiber a slightly nitrated cellulose by washing with water.

In testimony whereof I have signed my name to this specification.

. CHARLES SCHWARTZ.

Witnesses: PHILIPPA DEOGRANGAS, ADOLPHE BoHN. 

